Sous Vide Health & Safety: An In-Depth Guide For Home & Professional Chefs | The Tool Shed

As humans, we’re always a bit sceptical when trying something new, and even more so when it comes to what we put into our body.

For this reason, it’s only natural that some people have reservations over sous vide cooking, especially over the use of low temperatures to cook the food and the use of plastic bags in the cooking process.

However, the truth of the matter is that as long as you are careful and follow some basic health and safety rules, sous vide is completely safe.

We’re going to look through the steps which you need to take to ensure that your sous vide dishes come out tasty, tender, and most importantly, safe.

Cooking In Plastic

One of the worries that people have with sous vide is that of cooking in plastic bags, due to the presence of chemicals such as BPA (Bisphenol A) and phthalates.

The fear is that these additives can leak into the food and cause negative health impacts, especially in children.

Of course, there’s a simple and straightforward way to avoid these harmful chemicals, and that’s to ensure that you only use vacuum pouches which are 100% free of them.

Here at Sous Vide Tools, all of our vacuum sealer bags and pouches are food-grade and are made from a polyamide (PA) and polyethylene (PE) composite, which has been independently verified as being free of BPA, phthalates, and lead, so you can rest assured that they’re totally safe.

While these specialist bags have been proven to be safe, some of the cheaper plastic wraps sold to the catering trade, made from materials such as polyvinyl chloride (PVC) have not, and could prove harmful, especially when cooking fattier foods.

For this reason, it’s crucial that you only use approved sous vide vacuum bags, if only for your peace of mind!

If you’re still not convinced, remember, sous vide rarely uses a high enough temperature to soften the plastic anyway, so there’s nothing to worry about!

Cooking At Low Temperatures

Another major concern is that of cooking at such low temperatures. It’s certainly something most people aren’t used to, but in reality, the precise control that sous vide allows actually makes it safer than traditional techniques.

The ‘danger zone’ of food temperatures, in which bacteria multiply the most rapidly, is considered to be between 4.4˚C and 60˚C (the point of pasteurisation), but the majority of sous  vide products are cooked between 55C and 90˚C, so should be safe.

(Fish is a common exception, which some people cook at 46.5˚C – 52˚C, in which case you should only use sushi grade ocean fish which you would be willing to eat raw.)

The UK FSA (Food Standards Agency) requires that all cook-chilled foods are cooked at a heat process of either 70˚C/2 minutes or 90˚C/10 minutes (or equivalent).

(The choice of which process to choose depends upon the intended product shelf life. For example, products which will be stored for more than ten days should be given the equivalent of a 90˚C/10 minute process.)

If these standards aren’t met, then food is not considered to be safely cooked or pasteurised and isn’t safe to serve, either at home or in a professional kitchen.

The following tables give alternative times and temperatures which can be used to achieve the equivalent of 70˚C/2 minutes and 90˚C/10 minutes.

Remember, these temperatures and times refer to the slowest heating point of the product (the centre), so you’ll need to take a core temperature of the product.

To take a core temperature reading while your food is in the vacuum sealed pouch, place our special FDA Approved Foam Tape over the pouch to ensure that pressure isn’t lost and pierce with a thin needle thermometer, which should be accurate to ±1.0˚C, or preferably, ±0.5˚C.

Monitoring

When cooking in a professional environment, detailed paperwork has to be kept to prove that safe methods have been used in the preparation of the product.

This paperwork includes:

• Calibration records for the probe and water bath
• Temperature records of the water
• Core time/temperatures of foods
• Cooling records
• Storage time/temperatures
• Reheating time/temperature records for overnight cooking
• Evidence of staff training on the sous vide process

Below we’ve included an example of the type of hazard analysis which would be carried out in a professional kitchen:

Vacuum Sealing

When food is vacuum packed, as it is in sous vide cooking, an anaerobic (oxygen free) environment is created, which can potentially be a breeding ground for harmful bacteria such as salmonella, clostridium botulinum and listeria monocytogenes, if the food isn’t properly handled and hygiene standards met.

Providing you’re following all the right guidance and cooking your food at the right temperature for the right time, the issue will lie more with how you store the food after cooking.

If you aren’t going to be eating your food straight after cooking, you need to take extra care to store it properly.

Harmful bacteria such as clostridium botulinum cannot grow below 3˚C, so it’s recommended that vacuum-packed foods are kept between 3 and 8˚C for no longer than 10 days.

If you need to store your food for longer than ten days, then the following controls should be used:

• Equivalent heat process of 90˚C for ten minutes at the slowest heating point (as discussed earlier)
• pH of five or less in all parts of the food
• Minimum salt level of 3.5% in the water phase throughout all parts of the food
• Water activity of 0.97 or less in all components of the food

General Food Safety

Of course, there are also lots of general food safety rules which you should be following, no matter what you’re cooking, regardless of whether it’s sous vide or not, such as:

• Making sure your ingredients are fresh and of high quality, and that you thoroughly clean them beforehand.
• Separation of raw and high-risk foods such as raw meat and poultry.
• Using separate chopping boards and storage for different types of food such as veg, poultry and meat.
• Making sure all of your equipment is well maintained and regularly cleaned.
• Serving your food right away, or making sure to follow the right storage and chilling procedures.